(a) Field of the Invention
The present invention relates to a radio frequency identification (RFID) reader and a method for identifying an RFID tag thereof, and an apparatus for analyzing a reception power pattern.
(b) Description of the Related Art
A radio frequency identification (RFID) system includes an RFID reader and an RFID tag. The RFID system indicates a system that may provide various services such as positioning, a remote management, information exchange between objects, and the like in such a manner that the RFID reader identifies the RFID tag attached onto a corresponding object. The RFID system corresponds to a non-contact type identification system and thus may have no need to directly contact the RFID reader with the RFID tag, or to perform scanning within a visible band. Accordingly, the RFID system has been evaluated as technology that may replace a barcode that is a contact-type identification system, and a utilization range of the RFID system is being expanded.
The RFID system uses various frequency bands such as a low frequency (125 KHz, 135 KHz), a high frequency (13.56 MHz), an ultra high frequency (UHF) (433 MHz, 860-960 MHz), a microwave (2.45 GHz), and the like. In each frequency band, a utilization scheme or a utilization range of the RFID system may be different. Particularly, in a UHF band, the RFID system may perform a middle and long distance signal transmission, perform a relatively high speed transmission, and simultaneously identify a plurality of RFID tags. Accordingly, the RFID system is being widely used in all livings including a circulation and a distribution.
However, in a location such as a distribution center or a wholesale store, a plurality of RFID readers are attached to each gate that is an entrance of a product or a pallet and thereby are used. Thus, when the plurality of RFID readers exist in the same location, interference occurs between the RFID readers, which results in deteriorating an identification rate of an RFID tag.
Also, since all of a structure constituting the gate and an adjacent structure are composed of a metal component, reflected waves occur due to them, which may cause an RFID reader attached to the gate to read an undesired RFID tag. In the meantime, when the reflected waves do not occur, however, the undesired RFID tag exists within an identifiable range due to a narrow space, the RFID reader may read the undesired RFID tag. Also, when manufacturing the RFID tag, a difference of an identifiable distance may exist for each RFID tag due to various factors. Due to the difference of the identifiable distance, the RFID reader may also read the undesired RFID tag.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.